package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {


    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Override
    @Transactional
    public Result seckillVoucher(Long voucherId) {
        // 查询
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        // 判断秒杀是否开始
        if(voucher.getBeginTime().isAfter(LocalDateTime.now())){
            return Result.fail("秒杀还未开始");

        }
        // 判断秒杀是否结束
        if(voucher.getEndTime().isBefore(LocalDateTime.now())){
            return Result.fail("秒杀已经结束");
        }
        // 判断库存是否充足
        if(voucher.getStock() <= 0){
            return Result.fail("库存不足");
        }
        // 扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1") // set stock = stock - 1
                .eq("voucher_id", voucherId)
                //.eq("stock",voucher.getStock())  // where id =? and stock =?
                .gt("stock",0) // where id =? and stock > 0
                //.le("stock",voucher.getStock())  // where id =? and stock <= ?
                .update();
        if(!success){
            return Result.fail("库存扣减失败");
        }
        // 返回订单 id
        // 创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        // 订单 id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //用户 id
        Long userId= UserHolder.getUser().getId();
        voucherOrder.setUserId(userId);
        // 代金卷 id
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        return Result.ok(orderId);
    }
}
